title: Soil biological attributes in arsenic-contaminated gold mining sites after revegetation.
abstract: Recovery of arsenic contaminated areas is a challenge society faces throughout the world. Revegetation associated with microbial activity can play an essential role in this process. This work investigated biological attributes in a gold mining area with different arsenic contents at different sites under two types of extant revegetation associated with cover layers of the soil: BS, Brachiaria sp. and Stizolobium sp., and LEGS, Acacia crassicarpa, A. holosericea, A. mangium, Sesbania virgata, Albizia lebbeck and Pseudosamanea guachapele. References were also evaluated, comprising the following three sites: B1, weathered sulfide substrate without revegetation; BM, barren material after gold extraction and PRNH (private reserve of natural heritage), an uncontaminated forest site near the mining area. The organic and microbial biomass carbon contents and substrate-induced respiration rates for these sites from highest to lowest were: PRNH > LEGS > BS > B1 and BM. These attributes were negatively correlated with soluble and total arsenic concentration in the soil. The sites that have undergone revegetation (LEGS and BS) had higher densities of bacteria, fungi, phosphate solubilizers and ammonium oxidizers than the sites without vegetation. Principal component analysis showed that the LEGS site grouped with PRNH, indicating that the use of leguminous species associated with an uncontaminated soil cover layer contributed to the improvement of the biological attributes. With the exception of acid phosphatase, all the biological attributes were indicators of soil recovery, particularly the following: microbial carbon, substrate-induced respiration, density of culturable bacteria, fungi and actinobacteria, phosphate solubilizers and metabolic quotient.
authors.affiliation: Sector of Biology, Microbiology and Biological Processes, Department of Soil Science, Federal University of Lavras, Postal Box 3037, Lavras, MG, CEP 37200-000, Brazil.
authors.forename: Jessé Valentim
authors.initials: JV
authors.lastname: Dos Santos
authors.forename: Wesley
authors.initials: W
authors.lastname: de Melo Rangel
authors.forename: Amanda
authors.initials: A
authors.lastname: Azarias Guimarães
authors.forename: Paula Marcela
authors.initials: PM
authors.lastname: Duque Jaramillo
authors.forename: Márcia
authors.initials: M
authors.lastname: Rufini
authors.forename: Leandro Marciano
authors.initials: LM
authors.lastname: Marra
authors.forename: Maryeimy
authors.initials: M
authors.lastname: Varón López
authors.forename: Michele Aparecida
authors.initials: MA
authors.lastname: Pereira da Silva
authors.forename: Cláudio Roberto
authors.initials: CR
authors.lastname: Fonsêca Sousa Soares
authors.forename: Fatima Maria
authors.initials: FM
authors.lastname: de Souza Moreira
mesh_terms: D001151:Arsenic / Q000633:toxicity*; D001673:Biodegradation, Environmental; D018533:Biomass; D001938:Brazil; D004784:Environmental Monitoring; D008906:Mining; D010783:Photometry; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000633:toxicity*; D013054:Spectrophotometry, Atomic
chemical_list: D012987:Soil; D012989:Soil Pollutants; D001151:Arsenic